On the necessity and feasibility of revising and improving the methodology for calculating losses of petroleum products from evaporation based on the results of calculation and com-parative analysis

The aim of the work was to analyse the regulatory framework for accounting for petroleum product losses in Ukraine. A comparative and empirical analysis of three methods for determining petroleum product losses from evaporation was carried out. Calculations were made of petrol standing losses in vertical steel tanks with a nominal volume of 1,000, 2,000 and 3,000 m 3 in different climatic zones of Ukraine. The impact of tank filling level and saturated vapour pressure on losses was assessed. A comparative analysis showed that the EPA and Konstantynov methods demonstrate a physically justified reduction in losses with an increase in the filling level, as well as high sensitivity to climatic conditions. For the VCT-3000 tank, the relative error between calculations for the middle and southern climatic zones according to the Konstantynov method is 6.9-10.6%, and according to the EPA method – 8.5-12.0%. For the VCT-2000, these figures are 5.9-9.3% (Konstantynov) and 6.9-10.5% (EPA), and for the VCT-1000, they are 6.9-10.6% and 8.5-12%, respectively. However, calculations using the standard methodology showed virtually zero sensitivity to the climate zone (relative error ~0.26%), which contradicts actual operating conditions and leads to potentially significant errors in the assessment of volatile organic compound losses. This indicates the need to revise the current Ukrainian standards, taking into account modern physicochemical evaporation models. Additionally, the influence of saturated petroleum product vapour pressure according to Reid on the amount of losses was analysed. The results of calculations for the middle and southern climatic zones showed that an increase in saturated vapour pressure from 50 kPa to 80 kPa causes an approximately 1.6-fold increase in losses for all types of tanks studied. This confirms the high sensitivity of physical and mathematical methods to the physical and chemical properties of petroleum products, in contrast to the normative approach, which does not take this parameter into account. The results obtained can be used to develop an adapted combined methodology that combines the accuracy of international standards with the simplicity of normative accounting